Magnetic steel body, magnetic steel, manufacturing method of magnetic steel and motor

The embodiment of the invention provides a magnetic steel body, magnetic steel and a manufacturing method thereof, and a motor, the magnetic steel body comprises a comb back and a plurality of comb teeth, the comb teeth are arranged at intervals along the length direction, two ends of the comb back along the width direction are respectively provided with a row of comb teeth, a tooth groove is arranged between adjacent comb teeth, and the comb teeth and the comb back are integrally processed and formed. The magnetic steel comprises a magnetic steel body and a filling part, and the filling part is filled in the tooth groove. According to the magnetic steel body provided by the embodiment of the invention, the tooth grooves are processed through partial cutting, so that the processing steps and the processing time of the magnetic steel body are reduced, and the material waste caused by cutting is reduced. The comb tooth part of the magnetic steel body is subjected to heavy rare earth grain boundary diffusion tre